A series of tracer releases was carried out at the Millstone nuclear power plant1 located near Niantic on the Connecticut coast ,
Each release comprised an hour-long continuous emission of SFe from a stack at 48.3 m or of Freon-12 from three stacks at 29.1m. A total of 36 releases of SFe and 26 releases of Freon-12 were carried out. Concentrations were measured at 38 receptor locations along three arcs. The experimental set-up is illustrated in Figure 1.
Meteorological measurements were made at an on-site tower, at heights of 10 and 43 m. Winds were predominantly on-shore, with generally high speeds. The wind speed exceeded 7 in/s for most hours and reached more than 10m/s for several of the release periods. The majority of the releases were carried out during stable or neutral conditions.
The input data for the ADMS runs were taken from the AERMOD files downloaded from the United States Environmental Protection Agency website . These data included the arcwise maximum observed concentrations that have been used for comparison with the ADMS modelled concentrations.
This document compares the results of ADMS 220.127.116.11 (hereafter referred to as ADMS 5.0) with those of ADMS 18.104.22.168 (hereafter referred to as ADMS 4.2).